Trivia: Producer/screenwriter/director John Boorman deliberately chose renowned stage actors Nicol Williamson and Helen Mirren to play the sorcerer Merlin and the sorceress Morgana, knowing very well that Williamson and Mirren hated each other in real life (because of a disastrous stage production of Macbeth they worked on, years earlier). Boorman anticipated real friction, tension and anger between the two actors, which was the effect he wanted onscreen. On the contrary, the experience of working together in "Excalibur" completely changed Nicol Williamson and Helen Mirren into the best of friends.